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By P. M. Pearson

This paper describes the principles ()f systems engineering and their application to the various transport problems confronting the mining industry. The organization of mining operations into sub-system design problems is explained.

Jan 1, 1970

By J Nortier, J Dray

There is no single factor that determines the appropriate capacity for a mining project. It is driven by the size of the resource, the capacity of the market, the availability of capital, the availability of power, the availability of water, and a myriad of other considerations. There is also no single solution to the question of how big the project should be. However, to develop a project, the study team needs to select the configuration options that it regards as the best for the project. To be able to make this selection, the study team should consider the range of available options and do so at a level of detail that gives it confidence in the conclusion but does not lead to multiple detailed design exercises. Having considered the range of options, and with a clear definition of the project owner’s objectives and constraints, the work to be carried into feasibility studies can be focused appropriately. This paper discusses the process of completing strategic mine planning to identify project configuration options to assist in the selection of the processing plant throughput rate (Capacity Study) for a large greenfield open pit mine. The processes described in this paper allow for the basis of design to be set for subsequent studies that meets the objectives at a risk profile acceptable to the owner.

Jun 22, 2022

By Donald Bruce, Mark Harris, Wesley Schmutzler, James Sanders

"This paper evaluates the history, construction and most importantly the performance of two remedial seepage cutoff walls installed in two major dams in the United States. Beaver Dam, on the White River in northwest Arkansas, was completed in 1966 and seepage through the karstic limestone under the embankment was apparent almost immediately upon filling of the reservoir. Several attempts to stop the seepage by grouting were unsuccessful. In 1994 a cutoff wall consisting of secant piles drilled with 32"" diameter down-the-hole hammers to a maximum depth of 185'?was completed and the seepage was reduced to a negligible amount. It has been over 20 years since the completion of the cutoff wall, and all indications are that the cutoff wall is performing as expected. Walter F. George Lock and Dam on the Chattahoochee River near Fort Gaines, Georgia, was completed in 1963 and suffered the same problem as Beaver Dam due to the limestone on which the dam was founded. Cutoff walls were installed in both embankments (1980s) and solved the problem in these areas, but under-seepage at the concrete lock, dam and spillway structures increased to the point that remediation was essential. The cutoff wall had to be installed through 110'?of water and another 100'?into rock upstream of an active dam that continued to generate electricity during the construction of the cutoff wall. A secant pile wall, in combination with a diaphragm wall, was completed in front of these structures in 2004. It has been over 10 years since the completion this cutoff wall and, again, the cutoff wall is performing as expected. The paper describes the construction of these cutoffs, but focuses on the long-term performance in terms of controlling seepage and piezometric levels.BEAVER DAMBeaver Dam is located on the White River, 609 miles above its mouth, in Carroll County, Northwest Arkansas. The construction of the dam and Beaver Reservoir was authorized on September 1954 by the Congressional Flood Control Act for purposes of water supply, flood control and hydroelectric power generation. The dam site was selected in 1957: construction began in November 1960 and was completed in June 1966. (FIG. 1)"

Jan 1, 2017

By G. Lawrence, R. Pieters, A. Leung, T. Pedersen

The Main Zone and Waterline pit lakes at the Equity Silver Mine near Houston, BC (Canada) are the sites of a new 3-yr research program with three primary goals: 1) understanding controls on metal concentrations in the lakes; 2) using mesocosms to test a variety of remediation strategies; and 3) verifying and improving an existing coupled physical-geochemical model with the goal of improving predictions of pit lake water quality. Initial data from two summer surveys in the Main Zone pit lake reveal elevated dissolved metal concentrations (e.g. [Zn] as high as 800 µg/L) present in a two-meter-deep mixed layer, and elevated particulate metal concentrations towards the bottom of the water column. Hydroxide sludge, a byproduct of ARD treatment, is being discharged to the surface waters of the Main Zone pit lake. The sludge sinks rapidly to the lake bottom, leading to deep waters with elevated levels of dissolved O2 and total metals. By contrast, the deep waters of the proximal Waterline pit lake are mildly reducing, manifested by depletion of O2 and elevated levels of dissolved Fe. These reducing conditions have led to elevated levels of As (up to 1500 µg/L) in Waterline pit deep waters. The contrasting behavior of these two pit lakes, as well as the processes controlling metal concentrations in the lakes, will be discussed.

Jan 1, 2002

By Renzo D. Verastegui, T. C. Michael Law, Sitotaw Y. Fantaye, Alfredas Daugiala

"When completed, 520 Park Avenue will amend the Manhattan skyline and be one of the most prestigious high rise towers in New York City. The 52-story condominium building is located on a 60 by 100 feet lot on East 60th Street between Park and Madison Avenues. The geographically complex site is bounded by two fragile 5-story masonry buildings on the east and west, a mid-rise building on the north, and a New York City subway tunnel on the south. To add to this complexity, the ambitious development required 70 to 80 feet of excavation, mostly below groundwater level in highly permeable rock, to accommodate four levels of cellars. The new building also cantilevers 24 feet over a five-story historic building on the east. The limited footprint of the building coupled with large compressive and tensile axial loads, considerable base shear and over-turning moments, and the required deep excavation, presented unique foundation challenges. This paper describes how the challenges were solved with an innovative combination of permanent secant pile walls and drilled shafts.INTRODUCTIONThe project site is located at 45 East 60th Street, on the block bounded by East 61st Street to the north, East 60th Street to the south, Park Avenue to the east, and Madison Avenue to the west. As shown in Fig. 1, the site is surrounded on three sides by buildings sensitive to differential settlement. In addition, a NYCT underground subway structure lies below East 60th Street approximately 13 feet south of the site. The base of the subway structure is approximately 42 feet below the street.The project consisted of constructing a 52-story tall building. A portion of the superstructure cantilevers 24 feet over an adjacent five-story historic building. The underground construction for the new building involved a four-level basement, extending about 60 feet below ground surface. The excavation subgrade is much deeper than both the subway structure and the adjacent shallowly-founded building foundations."

Jan 1, 2016

By Jarc H

The steeply dipping silver/lead/zinc orebodies at Mount Isa mine have been extracted most recently by a combination of cut-and-fill and open stoping methods. Bench stoping was first used at Mount Isa Mine seven years ago to allow safe extraction of a highly stressed cut-and-fill stope. Subsequent benches have shown that the method offers significant cost and safety benefits through increased productivity and reduction in man exposure. The success of benching has lead to cut-and-fill mining being replaced at Mount Isa.Significant resources have been focussed to optimise benching. This paper describes the operational, planning, and research and development aspects which have contributed to the method to date. A brief look is also taken at the future direction of benching at Mount Isa.

Jan 1, 1992

By J. Illescas, N. C. Murray

This paper provides an economic comparison and technical evaluation of different approaches for copper recovery from small-scale resources such as historic tails, dumps, pond and pit water as well as acid mine/rock drainage. Factors such as the location, the availability and cost of reagents, power availability and cost and a local market for end product alter the preferred processing technique. A number of scenarios are presented and technologies considered include; solvent extraction, ion exchange, sulphide precipitation, cementation, copper sulphate crystallization, membrane (RO) and copper cathode production.

Jan 1, 2014

By M. Syamujulu

In 1994, Nkana smelter commissioned a multimillion US Dollar Chilean Teniente converter (CT) in its operations in order to improve its smelting technological base. The main objective was to reduce the overall smelting energy costs and increase the sulphur capture for sulphuric acid production to support the company?s leaching operations at Nchanga tailings leach plant. A decade of CT operations have since ensued following its installation and start-up. This paper provides a technical and operational audit of the performance of the CT in the first 10 years of its operations at Nkana smelter.

Jan 1, 2005

By Gary Kahn

In this document the VODR is discussed from a technical point of view and is intended to give the reader a feel for the design of the instrument, its technical specifications, and its limitations. It is not intended as a tutorial on the use of the instrument in the field.

Jan 1, 1989

By C. Tasker

Introduction In the Early part of 1930 the Ontario Research Foundation was asked by the Minister of Mines, the Hon. Charles McCrea, K.C., M.P.P., to undertake a technical and economic investigation of the Northern Ontario lignite deposit. This investigation has been under way since June, 1930, and has necessitated considerable work at the deposit, in the laboratories of the Foundation, and at test plants in Europe. All the work has been carried out in active co-operation with the Provincial Department of Mines, the Deputy Minister, Mr. T. F. Sutherland, and several of his technical colleagues being associated with members of the staff of the Foundation on the Advisory Committee, which has met at frequent intervals to co-ordinate and direct the various lines of research. An interim report was made to the Minister of Mines by the Director of the Foundation, Dr. H. B. Speakman, at the end of December, 1932, and is at present under consideration by the Minister. This report deals with the extent and character of the deposit, the methods and costs of mining, and the methods and costs of processing raw lignite, the characteristics of certain lignite products, and the technology and economics of present fuel utilization by railways, industry, and domestic users in northern Ontario. It is not the purpose of the author to discuss in this paper either the geology of the deposit or the economics of the mining, processing, and utilization of lignite, but rather to deal briefly with some of the technical problems investigated by the Foundation during the study of the characteristics and methods of utilization of Northern Ontario lignite. Some mention, however, of the work carried out to define the extent of the deposit is a prerequisite to any discussion of the nature of the lignite.

Jan 1, 1933

By Richard E. Hucko

The Coal Preparation Division of the Pittsburgh Mining Technology Center conducted an investigation to assess and compare the pyritic sulfur reduction potential of coal-pyrite flotation and high-gradient magnetic separation (HGMS). Tests were run on three coals--an Upper Freeport bed coal, a Lower Kittanning bed coal, and a Pittsburgh bed coal--to establish grade- recovery relationships characteristic of both processes. Representative portions of each coal sample were crushed to two top sizes--nominal minus 35 mesh (0.5 mm) and nominal minus 100 mesh (0.149 mm)--and subjected to conventional froth flotation. The froth product was then beneficiated by coal-pyrite flotation or HCMS to provide a direct technical comparison of the two processes. At minus 35 mesh (0.5 mm), the size normally employed for coal flotation, both coal-pyrite flotation and HGMS effectively separated pyrite from coal, and the performance of the two processes was essentially the same. At a size of minus 100 mesh (0.149 mm) , however, the performance of HGMS exceeded that of coal- pyrite flotation. The separations effected by HGMS were more efficient at minus 100 mesh (0.149 mm) than at minus 35 mesh (0.5 mm). On the other hand, it was concluded that either the effectiveness of coal-pyrite flotation decreases with diminishing top size, or the process has not been optimized to treat material finer than 35 mesh (0.5 mm).

Jan 1, 1981

By G. A. Vissac

MOISTURE in coal must be considered as an impurity, just the same as ash, from the standpoint of utilization of the coal. Being incombustible, it reduces directly the heating value of the coal, and in addition absorbs heat for its evaporation. Its presence means useless expenditures in handling and transportation. In coke plants, extra moisture reduces capacity and may cause damage to brick work and equipment. Accordingly, the removal of extra moisture can be considered just as important as the removal of other impurities, such as ashes, in the modern coal preparation plant. Moisture, which can be removed by heating the coal up to a temperature of 100°C, may be retained in various forms: 1. As a film, on the surface of each coal particle, and in the interstices between particles, retained by capillary forces. 2. Or "occluded" inside the coal particles. This occluded moisture may be either free moisture (as in a sponge), or hygroscopic moisture which varies with atmospheric conditions, (also called "regain").

Jan 1, 1949

By X. M. Yu

A large amount of polluted sludge is produced by a nonferrous metal factory after treating waste water with lime/ferrous salt. The concentration of arsenic in the dried sludge is high to 5.84%, a toxicity test is taken on the sludge according to GB5085.3-2007 and the extraction content is 15.75mg/L, which surpasses the arsenic extraction standard [As]=5mg/L, the sludge is categorized as hazardous waste. If put outside without disposal, it would be very harmful to environments. Here we report an optimum protocol to extract arsenic; S2- alkaline liquor is utilized to treat the arsenic sludge. At 85?, 10L 7% S2- liquor is added into 1kg dried sludge and the resulting mixture is stirred for 120min at 250r/min, then separated by centrifugation and the compressed waste residue dried naturally. The average arsenic content is 1.40mg/L, lower than GB5085.3-2007 Standard and arsenic-free residue is consistent with GB18598-2001 Standard, which can be bury safely. The extracted arsenic is transferred into copper arsensite for use as addictive in copper electrolysis and the waste water can be recycle after calcium is removed.

Jan 1, 2014

By L. E. Puddington, A. L. Mular

"Since the inception of spherical agglomeration, few investigations to exploit commercially the technique in the metallurgical field have been conducted. Of these, none appear to have been carried sufficiently far to demonstrate commercial feasibility.This paper describes a continuous agglomeration-separation process that can rapidly handle large tonnages of ore material. A small pilot plant de-signed from information obtained with the semi-batch unit described herein is currently in operation.In the absence of a reagent recovery system or cheap reagents, the process is probably not economically attractive for many common ores. However, for iron ores, the fuel content of the agglomerates can be used in a subsequent step such as direct reduction."

Jan 1, 1968

By Richard J. Mainiero

Traditional techniques for the experimental determination of toxic fumes produced by the detonation of high explosives are not applicable to blasting agents. To detonate properly, blasting agents require confinement, a significant booster, charge diameters of 3 inches (7.5 cm) or greater, and charge lengths greater than two-times the charge diameter. Without these conditions, blasting agents will not detonate at full order, leading to a misrepresentation of the gaseous products. A facility for detonating large, confined charges in a controlled volume has been constructed at the Pittsburgh Research Center’s Experimental Mine. The facility consists of a portion of mine entry (once used for full-scale mine explosion research and demonstrations) enclosed between two explosion proof bulkheads. Total volume of the chamber is 9,666 ft (274 m). The chamber is equipped with an air circulating system and is3 3vented using the mine's airflow. Up to 10-pound (4.5-kg) charges can be detonated in the chamber using a variety of confinements. For a typical test, the blasting agent is confined in a 4-inch (10-cm) schedule 80 steel pipe and initiated by a 3-inch (7.5-cm) diameter, 1-inch (2.5-cm) thick Pentolite booster. This combination of confinement and initiation yields a detonation velocity of about 4,000 m/sec for ANFO. This velocity is in line with that measured for blasting in the field. Twenty four 2-inch thick steel plates are suspended around the pipe bomb to stop shrapnel that would otherwise seriously damage the chamber. Following detonation of an explosive in the chamber, a circulating fan is run for about 10 minutes to uniformly mix the chamber atmosphere. Fumes samples are taken out of the chamber through 1/4-inch (0.6-cm) Teflon or polyethylene2tubes for analysis. The fumes are analyzed using bubblers or Vacutainers to collect samples for analysis by the analytical chemistry lab. The technique described here has been employed to determine the fumes produced by the detonation of a variety of ANFO formulations and commercial explosives. This technique may be developed as a standard test to measure fumes produced by blasting agents or may be used to provide data with which to develop a computer model that will reliably predict the expected fumes production based on chemical composition.

By Colonel Oattis E. Parks

The quantity of coal recovered by diamond coring techniques is not sufficient in many instances to make meaningful coking and/or ash fouling tests. Quantities in excess of that obtained by conventional coring techniques, usually in amounts exceeding 500 pounds, has been designated bulk sampling. During the past three years, AMAX Coal Company has utilized five methods of bulk sampling. It was our desire to obtain a bulk sample that was diagnostic of the seam by the most expedient and economical method. From the beginning all of our efforts have been directed to methods which would extract the required coal from slim boreholes which provide quick and inexpensive access to the coal seam, regardless of depth, terrain and accessability. In our efforts and investigation several large diameter cores have been taken from thick coal seams at relatively shallow depths in easily drilled rocks. On the other hand, for deeper thin seams multiple large diameter coring is more expensive and time consuming. It is somewhat less expensive when multiple cores are taken from a single slim borehole utilizing deflection coring, although considerable skill is necessary.

Jan 1, 1973

By W. W. Dudley

The U.S. Geological Survey, in support of underground testing of nuclear explosives, has developed a technique (Dudley, 1910) to predict the inflow of ground water to large underground chambers that are cylindrical in shape. By treating the chamber as a large-diameter well pumped at constant drawdown, the nonsteady discharge can be computed by the method of Hantush (1961) for analyzing flowing wells under leaky artesian conditions. In mining applications, whether for mineral recovery or for nuclear testing, the most serious departure from the conditions of Hantush's model results from the gradual enlargement of the opening under drained conditions. Inherent in the analytical technique is that the "well" is fully completed at the time that dewatering begins. Because safety is the prime concern, however, initial pumping systems or personnel evacuation procedures must be designed to handle the greatest conceivable inflow. DEFINITIONS Because somewhat different meanings are attached to similar words in different technical fields, the U.S. Geological Survey definitions (Lohman, 1970) of several hydrologic terms used in this report are given below. An aquifer is a formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells, and springs. A confining bed is a body of material lying stratigraphically adjacent to one or more aquifers and having a hydraulic conductivity distinctly lower than that of the aquifer. The total head (dimensions L) of a liquid at a given point is the sum of three components: (1) elevation head, he, which is equal to the elevation of the point above a datum; (2) pressure head, hp, which is the height of a column of static water that can be supported by the static pressure at the point; and (3) velocity head, hv, which is the height the kinetic energy of the liquid is

Jan 1, 1971

By P. C. Parsons, G. C. Milligan

"IN FIELD WORK in the Cape Breton Highlands, which are heavily covered with vegetation, it is necessary to run traverses along the valleys of small brooks. We encountered difficulty in closing such traverses, and the following technique was developed to solve this problem. It has been tested in the field for four seasons by several people, and found to be simple, efficient and more accurate than any other compass-and-pace system of which we are aware. So far as we can find, the technique has not been described previously. It may be of use to others.The Cape Breton Highlands of Nova Scotia consist of hills of old intrusive and metamorphosed sedimentary rocks protruding up to 1,000 feet above the general level of the younger sediments which underlie the valleys. The flat hill-tops are the remnants of a plateau; drainage off the edge of this plateau has produced many small steep brooks. They occupy valleys which are up to 800 feet deep, and V-shaped in cross section, with steep sides covered by mixed conifers and hardwoods. The stream at the bottom is rarely more than a few feet wide, with a negligible meander belt, but with many bends, rapids and falls. Visibility along the stream, in consequence, is rarely more than a few hundred feet, and in many places much less.It was found impractical to map the streams by the method of meander lines, as described in many standard surveying texts and hand-books. The limited visibility, and the numerous bends of the brooks, necessitated many corners. Every corner introduces errors. To 'close' a survey with 40 or 50 such corners proved either very time-consuming or impossible. In most cases, however, the general direction of a valley may be obtained from an aerial photograph, or by direct observation, and this became the basis of the method adopted."

Jan 1, 1971

By A. Zangooi

Frothers play major roles in flotation through interaction at the air/water interface. A method of determining frother adsorption density (coverage), i.e., the number of molecules per unit of interfacial area of bubble surface, is introduced. The technique is based on mass balancing the frother around a continuously operated bubble column. The mass balance requires collection of bubbles before they burst. The column design and operating procedure is reviewed, and some preliminary results discussed. Keywords: flotation, colorimetric frother analysis technique, frother mass balance, coverage

Sep 1, 2012

By J. A. Finch

"A method of sampling and presenting bubbles for imaging for use in full-size flotation cells is described. The device (bubble viewer) comprises a tube attached to a sealed glass viewing chamber. The assembly is first filled with frother-containing water (to prevent coalescence) and the tube immersed at the desired location below the froth. For a few minutes bubbles are collected in the viewer free from slurry and are readily imaged. To reduce bubble overlap and the problem of defining the plane of view, the viewing chamber has a sloped side. Bubbles rise, encounter this slope, spread into a single plane and slide up. This simple expedient virtually eliminates overlap and provides an unambiguous focus plane - the underside of the sloped glass. The bubble image is captured and processed to give size data. The bubble viewer has been employed at several concentrators on different types of flotation cells. Examples of the images are given. The impact of position in the cell and the effect of changing gas rate on bubble size are illustrated. This technique provides a sensitive measure of the effects of process variables on bubble size.INTRODUCTIONDespite the extensive use of flotation in the mineral processing industry, the methodology employed for cell design is largely based on empirical rules rather than on first principles. One of the main reasons for this state of affairs is that the local flow structures encountered in industrial-scale machines are very complex. These flow structures are difficult to simulate under the controlled conditions of the laboratory and the difficulty to solve the mathematical models that treat the randomness of such flows also mean theoretical treatment is limited. Understanding flotation cell hydrodynamics requires reliable data, which involves the implementation of measurement techniques capable of performing both at the laboratory- and the industrial-scale, In addition, it is desirable that such techniques are amenable to automation to reduce extensive manual intervention in the data collection process."

Jan 1, 2002